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7728819c | 1 | // SPDX-License-Identifier: GPL-2.0+ |
89214f00 SA |
2 | /* |
3 | * Copyright 2010 Broadcom | |
4 | * Copyright 2012 Simon Arlott, Chris Boot, Stephen Warren | |
5 | * | |
89214f00 SA |
6 | * Quirk 1: Shortcut interrupts don't set the bank 1/2 register pending bits |
7 | * | |
8 | * If an interrupt fires on bank 1 that isn't in the shortcuts list, bit 8 | |
9 | * on bank 0 is set to signify that an interrupt in bank 1 has fired, and | |
10 | * to look in the bank 1 status register for more information. | |
11 | * | |
12 | * If an interrupt fires on bank 1 that _is_ in the shortcuts list, its | |
13 | * shortcut bit in bank 0 is set as well as its interrupt bit in the bank 1 | |
14 | * status register, but bank 0 bit 8 is _not_ set. | |
15 | * | |
16 | * Quirk 2: You can't mask the register 1/2 pending interrupts | |
17 | * | |
18 | * In a proper cascaded interrupt controller, the interrupt lines with | |
19 | * cascaded interrupt controllers on them are just normal interrupt lines. | |
20 | * You can mask the interrupts and get on with things. With this controller | |
21 | * you can't do that. | |
22 | * | |
23 | * Quirk 3: The shortcut interrupts can't be (un)masked in bank 0 | |
24 | * | |
25 | * Those interrupts that have shortcuts can only be masked/unmasked in | |
26 | * their respective banks' enable/disable registers. Doing so in the bank 0 | |
27 | * enable/disable registers has no effect. | |
28 | * | |
29 | * The FIQ control register: | |
30 | * Bits 0-6: IRQ (index in order of interrupts from banks 1, 2, then 0) | |
31 | * Bit 7: Enable FIQ generation | |
32 | * Bits 8+: Unused | |
33 | * | |
34 | * An interrupt must be disabled before configuring it for FIQ generation | |
35 | * otherwise both handlers will fire at the same time! | |
36 | */ | |
37 | ||
38 | #include <linux/io.h> | |
39 | #include <linux/slab.h> | |
40 | #include <linux/of_address.h> | |
41 | #include <linux/of_irq.h> | |
41a83e06 | 42 | #include <linux/irqchip.h> |
89214f00 | 43 | #include <linux/irqdomain.h> |
89214f00 SA |
44 | |
45 | #include <asm/exception.h> | |
5702941e | 46 | |
89214f00 SA |
47 | /* Put the bank and irq (32 bits) into the hwirq */ |
48 | #define MAKE_HWIRQ(b, n) ((b << 5) | (n)) | |
49 | #define HWIRQ_BANK(i) (i >> 5) | |
50 | #define HWIRQ_BIT(i) BIT(i & 0x1f) | |
51 | ||
52 | #define NR_IRQS_BANK0 8 | |
53 | #define BANK0_HWIRQ_MASK 0xff | |
54 | /* Shortcuts can't be disabled so any unknown new ones need to be masked */ | |
55 | #define SHORTCUT1_MASK 0x00007c00 | |
56 | #define SHORTCUT2_MASK 0x001f8000 | |
57 | #define SHORTCUT_SHIFT 10 | |
58 | #define BANK1_HWIRQ BIT(8) | |
59 | #define BANK2_HWIRQ BIT(9) | |
60 | #define BANK0_VALID_MASK (BANK0_HWIRQ_MASK | BANK1_HWIRQ | BANK2_HWIRQ \ | |
61 | | SHORTCUT1_MASK | SHORTCUT2_MASK) | |
62 | ||
63 | #define REG_FIQ_CONTROL 0x0c | |
64 | ||
65 | #define NR_BANKS 3 | |
66 | #define IRQS_PER_BANK 32 | |
67 | ||
c376023b NP |
68 | static const int reg_pending[] __initconst = { 0x00, 0x04, 0x08 }; |
69 | static const int reg_enable[] __initconst = { 0x18, 0x10, 0x14 }; | |
70 | static const int reg_disable[] __initconst = { 0x24, 0x1c, 0x20 }; | |
71 | static const int bank_irqs[] __initconst = { 8, 32, 32 }; | |
89214f00 SA |
72 | |
73 | static const int shortcuts[] = { | |
74 | 7, 9, 10, 18, 19, /* Bank 1 */ | |
75 | 21, 22, 23, 24, 25, 30 /* Bank 2 */ | |
76 | }; | |
77 | ||
78 | struct armctrl_ic { | |
79 | void __iomem *base; | |
80 | void __iomem *pending[NR_BANKS]; | |
81 | void __iomem *enable[NR_BANKS]; | |
82 | void __iomem *disable[NR_BANKS]; | |
83 | struct irq_domain *domain; | |
84 | }; | |
85 | ||
86 | static struct armctrl_ic intc __read_mostly; | |
8783dd3a | 87 | static void __exception_irq_entry bcm2835_handle_irq( |
5702941e | 88 | struct pt_regs *regs); |
bd0b9ac4 | 89 | static void bcm2836_chained_handle_irq(struct irq_desc *desc); |
89214f00 SA |
90 | |
91 | static void armctrl_mask_irq(struct irq_data *d) | |
92 | { | |
93 | writel_relaxed(HWIRQ_BIT(d->hwirq), intc.disable[HWIRQ_BANK(d->hwirq)]); | |
94 | } | |
95 | ||
96 | static void armctrl_unmask_irq(struct irq_data *d) | |
97 | { | |
98 | writel_relaxed(HWIRQ_BIT(d->hwirq), intc.enable[HWIRQ_BANK(d->hwirq)]); | |
99 | } | |
100 | ||
101 | static struct irq_chip armctrl_chip = { | |
102 | .name = "ARMCTRL-level", | |
103 | .irq_mask = armctrl_mask_irq, | |
104 | .irq_unmask = armctrl_unmask_irq | |
105 | }; | |
106 | ||
107 | static int armctrl_xlate(struct irq_domain *d, struct device_node *ctrlr, | |
108 | const u32 *intspec, unsigned int intsize, | |
109 | unsigned long *out_hwirq, unsigned int *out_type) | |
110 | { | |
111 | if (WARN_ON(intsize != 2)) | |
112 | return -EINVAL; | |
113 | ||
114 | if (WARN_ON(intspec[0] >= NR_BANKS)) | |
115 | return -EINVAL; | |
116 | ||
117 | if (WARN_ON(intspec[1] >= IRQS_PER_BANK)) | |
118 | return -EINVAL; | |
119 | ||
120 | if (WARN_ON(intspec[0] == 0 && intspec[1] >= NR_IRQS_BANK0)) | |
121 | return -EINVAL; | |
122 | ||
123 | *out_hwirq = MAKE_HWIRQ(intspec[0], intspec[1]); | |
124 | *out_type = IRQ_TYPE_NONE; | |
125 | return 0; | |
126 | } | |
127 | ||
96009736 | 128 | static const struct irq_domain_ops armctrl_ops = { |
89214f00 SA |
129 | .xlate = armctrl_xlate |
130 | }; | |
131 | ||
132 | static int __init armctrl_of_init(struct device_node *node, | |
a493f339 EA |
133 | struct device_node *parent, |
134 | bool is_2836) | |
89214f00 SA |
135 | { |
136 | void __iomem *base; | |
137 | int irq, b, i; | |
138 | ||
139 | base = of_iomap(node, 0); | |
140 | if (!base) | |
e81f54c6 | 141 | panic("%pOF: unable to map IC registers\n", node); |
89214f00 SA |
142 | |
143 | intc.domain = irq_domain_add_linear(node, MAKE_HWIRQ(NR_BANKS, 0), | |
144 | &armctrl_ops, NULL); | |
145 | if (!intc.domain) | |
e81f54c6 | 146 | panic("%pOF: unable to create IRQ domain\n", node); |
89214f00 SA |
147 | |
148 | for (b = 0; b < NR_BANKS; b++) { | |
149 | intc.pending[b] = base + reg_pending[b]; | |
150 | intc.enable[b] = base + reg_enable[b]; | |
151 | intc.disable[b] = base + reg_disable[b]; | |
152 | ||
153 | for (i = 0; i < bank_irqs[b]; i++) { | |
154 | irq = irq_create_mapping(intc.domain, MAKE_HWIRQ(b, i)); | |
155 | BUG_ON(irq <= 0); | |
156 | irq_set_chip_and_handler(irq, &armctrl_chip, | |
157 | handle_level_irq); | |
d17cab44 | 158 | irq_set_probe(irq); |
89214f00 SA |
159 | } |
160 | } | |
89214f00 | 161 | |
a493f339 EA |
162 | if (is_2836) { |
163 | int parent_irq = irq_of_parse_and_map(node, 0); | |
164 | ||
165 | if (!parent_irq) { | |
e81f54c6 RH |
166 | panic("%pOF: unable to get parent interrupt.\n", |
167 | node); | |
a493f339 EA |
168 | } |
169 | irq_set_chained_handler(parent_irq, bcm2836_chained_handle_irq); | |
170 | } else { | |
171 | set_handle_irq(bcm2835_handle_irq); | |
172 | } | |
173 | ||
5702941e | 174 | return 0; |
89214f00 SA |
175 | } |
176 | ||
a493f339 EA |
177 | static int __init bcm2835_armctrl_of_init(struct device_node *node, |
178 | struct device_node *parent) | |
179 | { | |
180 | return armctrl_of_init(node, parent, false); | |
181 | } | |
182 | ||
183 | static int __init bcm2836_armctrl_of_init(struct device_node *node, | |
184 | struct device_node *parent) | |
185 | { | |
186 | return armctrl_of_init(node, parent, true); | |
187 | } | |
188 | ||
189 | ||
89214f00 SA |
190 | /* |
191 | * Handle each interrupt across the entire interrupt controller. This reads the | |
192 | * status register before handling each interrupt, which is necessary given that | |
193 | * handle_IRQ may briefly re-enable interrupts for soft IRQ handling. | |
194 | */ | |
195 | ||
de58e52f | 196 | static u32 armctrl_translate_bank(int bank) |
89214f00 | 197 | { |
de58e52f | 198 | u32 stat = readl_relaxed(intc.pending[bank]); |
89214f00 | 199 | |
de58e52f EA |
200 | return MAKE_HWIRQ(bank, ffs(stat) - 1); |
201 | } | |
202 | ||
203 | static u32 armctrl_translate_shortcut(int bank, u32 stat) | |
204 | { | |
205 | return MAKE_HWIRQ(bank, shortcuts[ffs(stat >> SHORTCUT_SHIFT) - 1]); | |
89214f00 SA |
206 | } |
207 | ||
de58e52f | 208 | static u32 get_next_armctrl_hwirq(void) |
89214f00 | 209 | { |
de58e52f EA |
210 | u32 stat = readl_relaxed(intc.pending[0]) & BANK0_VALID_MASK; |
211 | ||
212 | if (stat == 0) | |
213 | return ~0; | |
214 | else if (stat & BANK0_HWIRQ_MASK) | |
215 | return MAKE_HWIRQ(0, ffs(stat & BANK0_HWIRQ_MASK) - 1); | |
216 | else if (stat & SHORTCUT1_MASK) | |
217 | return armctrl_translate_shortcut(1, stat & SHORTCUT1_MASK); | |
218 | else if (stat & SHORTCUT2_MASK) | |
219 | return armctrl_translate_shortcut(2, stat & SHORTCUT2_MASK); | |
220 | else if (stat & BANK1_HWIRQ) | |
221 | return armctrl_translate_bank(1); | |
222 | else if (stat & BANK2_HWIRQ) | |
223 | return armctrl_translate_bank(2); | |
224 | else | |
225 | BUG(); | |
89214f00 SA |
226 | } |
227 | ||
8783dd3a | 228 | static void __exception_irq_entry bcm2835_handle_irq( |
89214f00 SA |
229 | struct pt_regs *regs) |
230 | { | |
de58e52f EA |
231 | u32 hwirq; |
232 | ||
233 | while ((hwirq = get_next_armctrl_hwirq()) != ~0) | |
d7e3528e | 234 | handle_domain_irq(intc.domain, hwirq, regs); |
89214f00 | 235 | } |
5702941e | 236 | |
bd0b9ac4 | 237 | static void bcm2836_chained_handle_irq(struct irq_desc *desc) |
a493f339 EA |
238 | { |
239 | u32 hwirq; | |
240 | ||
241 | while ((hwirq = get_next_armctrl_hwirq()) != ~0) | |
242 | generic_handle_irq(irq_linear_revmap(intc.domain, hwirq)); | |
243 | } | |
244 | ||
245 | IRQCHIP_DECLARE(bcm2835_armctrl_ic, "brcm,bcm2835-armctrl-ic", | |
246 | bcm2835_armctrl_of_init); | |
247 | IRQCHIP_DECLARE(bcm2836_armctrl_ic, "brcm,bcm2836-armctrl-ic", | |
248 | bcm2836_armctrl_of_init); |